Is performance better with show changes on or off?

When track changes is turned on, I prefer to work with show changes off. However, not showing the changes seems to slow performance. In fact, a message sometimes appears saying that performance would be better with show changes on.
Someone in a post said that turning off show changes could improve performance. So, there is contradictory information. The poster is wrong or something has changed.

It has occurred to me that perhaps the upgrade to 5.4 has improved the performance when show changes is off. Performance with track changes is certainly slower and I want to do everything possible to improve it.

Can anyone shed light on this?